It's not in Grove, but it _is_ in the New Harvard Dictionary of Music.
(And they do use "Festschriften" as the plural.)
--pH <[log in to unmask]> http://library.wustl.edu/~manynote
/\ "'Jever take'n try to give an ironclad leave to
-\-\-- o yourself from a three-rail billiard shot?"
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